Even the extra hit points don't seem worth it, but when you realize that it now takes TWO hits from a few defenses to kill a Level 6 Archer where a Level 5 Archer only needs one hit. So in effect, they actually have *double* the hit points of a Level 5.
And if you are going to 'rage' over the time of the upgrade... just quit now. Most of TH9, and definitely ALL of TH10 is not for you.
Classic Joke:
Patient: Doctor, it hurts when I do THIS! Doctor: Well, don't do that!
Clash of Clans version:
Player: It hurts when I play in Legend League. Logic: Well, don't do that!
Correct
L7 Archer Tower, One hit becomes Two hits
L5 Mortar, One hit becomes Two hits
L6 Wizard Tower, One hit becomes Two hits
L5 Cannon, Two hits becomes Three hits
L1 Hidden Tesla, Two hits becomes Three hits
L3 Wizard Tower, Three hits becomes Four hits
L4 XBow, Four hits becomes Five hits
(and a few at lower levels too)